Electrical switches with external return springs

ABSTRACT

The present invention provides a new switch having a return spring which is mounted outside the casing in which the carriage and contactor are movable. An operating lever or other member extends into the casing to engage the carriage. Preferably, the spring is in the form of a torsion spring mounted on the pivot which supports the lever. In one embodiment, the spring has arms which extend into the casing through an opening therein, and then into a recess in the carriage. When the carriage is moved in opposite directions, it engages and moves the opposite arms of the spring. The opposite ends of the opening in the casing provide stops which are engageable with the arms to maintain initial stress in the spring. In another embodiment, the arms are engageable by tabs or other elements on the operating lever.

United States Patent Raab [54] ELECTRICAL SWITCHES WITH EXTERNAL RETURNSPRINGS [72] Inventor: Andrew F. Raab, Morton Grove, Ill. [73] Assignee:Indak Manufacturing Corp., Northbrook,

[22] Filed: May 21, 1970 21 Appl. No.: 39,289

[52] US. Cl. ..200/153 K, 200/ l 6 R, 74/523 51 Int. Cl. ..H0lh 15 02[58] Field of Search ..200/l6 IR, 153 K; 74/523; 251/242, 243

[56] References Cited UNITED STATES PATENTS 3,502,825 3/1970 Bailey eta1 200/16 R 2,725,432 11/1955 Brown... ..200/153 K X 2,929,041 3/1960Pettit..... 200/153 K X 3,072,757 l/l963 Gluck ..200/l6 R 3,469,0429/1969 Sandor .200/153 K X 3,223,794 12/1965 Hoy et a1 ..200/16 R2,759,075 8/1956 Hults ..200/l53 K UX FOREIGN PATENTS OR APPLICATIONS632,546 11/1949 Great Britain ..200/ 153 K Primary Examiner-Robert K.Schaefer Assistant Examiner-Robert A. Vanderhye AttorneyBunneister,Palmatier & Hamby ABSTRACT The present invention provides anew switchhaving a return spring which is mounted outside the casing in which thecarriage and contactor are movable. An operating lever or other memberextends into the casing to engage the carriage Preferably, the spring isin the form of a torsion spring mounted on the pivot which supports thelever. In one embodiment, the spring has arms which extend into thecasing through an opening therein, and then into a recess in thecarriage. When the carriage is moved in opposite directions, it engagesand moves the opposite arms of the spring. The opposite ends of theopening in the casing provide stops which are engageable with the armsto maintain initial stress in the spring. In another embodiment, thearms are engageable by tabs or other elements on the operating lever.

PATENTEUJUN 6 I972 3. 668,353

N VE N TOR Andrew I. Raab PATENTEDJUH 6l972 3,668,353

SHEET 2 OF 4 Bra, 5 FIG. 11

FIG, 10

PATENTEDJUH 6|972 3,668,353

sum am 4 ELECTRICAL SWITCHES WITI-I EXTERNAL RETURN SPRINGS Thisinvention relates to electrical switches which are especially welladapted for automotive service, but will find many other applications.

One object of the present invention is to provide new and improvedswitches of the spring return type.

A further object is to provide a new and improved electrical switch inwhich the return spring is mounted outside the casing in which thecarriage and contactor are movable. In this way, the size of the returnspring is not limited by the space in the casing. A strong anddependable return spring can be provided at very low cost. The samereturn spring, and the associated supporting components, can be employedwith a wide variety of switches, having various contactor and contactarrangements. Moreover, any particular switch construction can readilybe provided, either with or withoutthe return spring.

Generally, the switch of the present invention comprises a casing inwhich an insulating carriage is movable. One or more contactorsaremounted on the carriage and are engageable with fixed contacts. Thepresent invention can be applied to switches with a wide variety ofcontactor and contact arrangements. The switch comprises an operatingmember disposed outside the casing and having a member extending intothe casing to operate the carriage. Such operating member is preferablyin the form of a lever pivoted on a bracket or the like on the outsideof the casing. A return spring is disposed outside the casing,preferably in the form of torsion spring mounted on the pivot whichsupports the lever. The spring is engageable with at least oneconnecting element which is movable with the operating member and thecarriage. In one embodiment, the torsion spring has arms which extendinto the casing through an opening therein. The arms are engageable bythe carriage when it is moved in opposite directions. Thus, the springbiases the carriage toward an initial position. Preferably, the ends ofthe opening in the carriage provide stops which are engageable with thearms of the spring to maintain an initial stress therein.

In another embodiment, the arms of the torsion spring are engageable bytabs or other elements on the operating lever. Here again, the arms ofthe spring are engageable with stops on the casing.

Further objects, advantages and features of the present invention willappear from the following description taken in connection with theaccompanying drawings, in which:

FIG. 1 is a side elevational view of a switch to be described as anillustrative embodiment of the present invention.

FIGS. 2 and 3 are front and rear elevations of the switch.

FIG. 4 is an elevation of the switch viewed from the opposite side, asindicated by the line 4-4 in FIG. 2.

FIG. 5 is a top view of the switch.

FIG. 6 is a rear view with the contact board removed and positionedalong side theswitch.

FIG. 7 is a view similar to FIG. 6 removed.

FIG. 8 is a fragmentary section taken generally along the line 8-8 inFIG. 5, the switch being shown in its initial or neutral position.

FIG. 9 is a view similar to FIG. 8 but showing the switch with thecarriage moved upwardly from its neutral position.

FIG. 10 is a view similar to FIG. 8 but showing the switch with thecarriage moved downwardly from its neutral position.

FIG. 11 is a horizontal section, taken generally along the line 11-11 inFIG. 8.

FIG. 12 is an elevation showing the relationship between the contactorand the contact board, with the contactor in a position corresponding toFIG. 9. 4

FIG. 13 is a perspective view of the contactor.

FIGS. 14 and 15 are perspective views showing the rear and front sidesof the carriage.

FIG. 16 is a side elevation of a modified switch to be described asanother embodiment of the present invention.

FIGS. l7, l8 and 19 are front, top and rear views of the switches ofFIG. 16.

but with the carriage FIG. 20 is a vertical section, taken generallyalong the broken line 20-20 in FIG. 18.

FIG. 21 is a horizontal section, taken generally along the line 21-21 inFIG. 16.

FIG. 22 is a front view detached from the switch, 22-22 in FIG. 16.

FIG. 23 is a rear view of the switch with the contact board removed,generally as indicated by the line 23-23 in FIG. 16.

FIG. 24 is a view similar to FIG. 23 but with the carriage and contactormoved.

FIGS. 25, 26 and 27 are perspective views of the casing, operating leverand contactor for the switch of FIG. 16.

FIGS. 28 and 29 are perspective views of the front and rear sides of thecarriage for the switch of FIG. 16.

FIG. 30 is a diagrammatic sectional view taken longitudinally throughthe contactor and showing the manner in which it tilts or rocks when itis moved from its neutral position.

As just indicated, FIGS. ll5 illustrate an electrical switch 30 which isparticularly well adapted for automotive service, but will find manyother applications. The illustrated switch was designed particularly tocontrol the rear window heater for an automobile. However, it will beunderstood that the invention is applicable to many types of switches.

' The illustrated switch 30 comprises a casing 32, with a carriage 34movable therein, as shown to best advantage in FIG. 8. The carriage 34is preferably made of an insulating material, such as a suitableresilient plastic. One or more contactors are mounted on and movablewith the carriage 34. In this case, there is a single contactor 36.

Various contact means may be provided for engagement by the contactor36. As shown, three contact points 38, 39 and 40 are engageable by thecontactor 36. The contact points 38, 39 and 40 are in the form of thespherically rounded heads of rivets 42,43 and 44, extending throughcorresponding opening in an insulating contactor or terminal board 46.Terminals 48, 49 and 50 are secured to the board 46 by the rivets 42, 43and 44 of the contact board, shown generally as indicated by the lineThe switch 30 is preferably provided with spring means to press thecontactor 36 against the contacts 38, 39 and 40. As

shown, a coil spring 52 is connected between the carriage 34 and thecontactor 36. The spring 52 is located in a circular recess 54 formed inthe carriage 34. In the illustrated switch, the casing 32 issubstantially rectangular, and the carriage 34 is slidable along thelength of the casing. The contactor 36 is generally rectangular inshape. However, it will be understood that the manner in which thecarriage is movable within the casing may be varied.

The switch 30 is provided with operating means for moving the carriage34. As illustrated, such operating means take the form of a lever orother member 56, disposed outside the casing 34. The illustrated lever56 has an arm 58 which extends into the casing 34 through a slot orother opening 60. The arm 58 has a rounded end portion 62 which isreceived in an opening 64, formed in the carriage 34. The lever 56 has aprojecting portion 66 which serves as a handle.

The illustrated lever 56 is pivotally mounted on a bracket 68 extendingforwardly from a mounting plate 70, which is riveted or otherwisesecured to the casing 32. A pivot 72 extends through an opening 74 inthe lever 56 and is riveted or otherwise secured to the bracket 68.

Spring means are provided to bias the carriage 34 and the lever 56 to aneutral or initial position, as shown in FIGS. 1 and 8. This position isdesignated N in FIG. 1. The lever 56 is swingable in one direction to aposition designated START, and in the opposite direction to a positiondesignated OFF. The corresponding positions of the carriage 34 are shownin FIGS. 9 and 10. Resilient resistance is afforded by the spring meansto the movement of the carriage 34 and the lever 56 away from theneutral position.

Various return spring arrangements may be employed. As illustrated, theswitch 30 comprises a torsion spring 76 disposed outside the casing 34.As illustrated, the spring 76 is mounted on an enlarged portion 78 ofthe pivot 72. The spring 76 has arms 80 and 82 for engagement byconnection elements on the carriage 34. Thus, the arms 80 and 82 extendinto the casing 32 through a slot or other opening 84 therein. Themounting plate 70 has a cutout or opening 86 which exposes the slot 84,and also the slot 60.

The rear ends of the arms 80 and 82 are received in a recess or otheropening 88 in the carriage 34. The ends of the slot 84 in the casing 32act as stops for the spring arms 80 and 82, to locate the neutralposition of the carriage 34 and the lever 56. Preferably the spring 76is given an initial stress, which is maintained by the engagement of thespring arms 80 and 82 with the ends of the slot 84.

' When the handle 66 is swung upwardly to the START position, as shownin FIG. 1, the carriage 34 I is moved downwardly, as shown in FIG. 10.The upper end of the recess 88 in the carriage 34 pushes the spring arm80 downwardly, so that the spring affords resilient resistance to thedownward movement of the carriage.

- When the handle 66 is swung downwardly to the OFF position, as shownin FIG. 1, the carriage 34 is moved upwardly, as shown in FIG.'9. Thelower end of the recess 88 pushes the spring arm 82 upwardly, so thatthe spring 76 affords a resilient restoring force, tending to return thecarriage 34 to its neutral position.

The external return spring '76 provides a switch construction which isparticularly easy to assemble. The spring 76 and the lever 56 aremounted on the pivot 72. The arms 80 and 82 of the spring 76 are pressedtogether and inserted through the slot 84 in the casing 32. The pivot 72is then riveted to the bracket 68. It will be seen that the pivot 72 hasa head or flange 90 which retains the spring 76 on the enlarged portion78 of the pivot. The spring 76 does not engage the bracket 68 or thelever 56 so that these components do not need to be adapted or modifiedto accommodate the spring.

The carriage 34 maysimply be inserted into the casing 32, in such amanner that the ends of the arms 80 and 82 will be received in therecess 88. The spring 52, contactor 36, and terminal board 46 are thenadded to complete the assembly. The terminal board 46 may be secured tothe casing 32 in any suitable manner. As shown the casing 32 is formedwith tabs 92 which are bent behind the terminal board 46 to secure it inplace. I

The arrangement of the return spring 76'has the additional advantagethat a large and sturdy spring may be employed, without any limitationdue to the size of the casing 32. The strength and the construction ofthe spring 76 can be varied to suit different switch designs, withoutmaking any change in the casing 32 or the carriage 34. Moreover, thesame spring construction can be used for many different switch designs,involving variations in the carriage 34, or in the contactor 36 and theassociated contact points.

FIG. 12 shows the contactor 36 in its OFF position, in which thecontactor engages only the contact point 39, and thus does not completeany circuit. The neutral position of the contactor 36 is indicated inbroken lines. In this position, the contactor engages the contact points38 and 39. The circuit thus established can be employed as the holdingcircuit for a relay or for any other desired purpose. The START positionof the contactor 36 is also indicated in broken lines. In this position,the contactor engages the contact points 38 and 40. The connection thusestablished can be employed to energize the relay, or for any otherdesired purpose.

FIGS. 16-29 illustrate a modified switch 100 having a casing 102. Acarriage 104 is movable in the casing 102. As shown to best advantage inFIG. 23, a contactor 106 is mounted on and movable with the carriage104.

' As shown in FIG. 22,- the switch 100 is provided with contact meanscomprising three contact points 111-1 13, mounted on an insulatingterminal board 116 which closes the rear side of the casing 102. Asbefore, tabs 1 18 are provided to secure the board 116 tothe casingI02.The contact points Ill-I13 have portions which extend throughcorresponding holes in the insulating board 116 and are connected to orformed integrally with terminals pins 121-123, shown to best advantagein FIG. 19. The board 116 also carries two pilot or locating pins 124and 125, connected to rivet heads 124a and 125a which are thinner thanthe contact points 111-113 and thus are not engaged by the contactor 106in any of the three operating positions thereof. It will be seen fromFIG. 22 that the board 116 is provided with an insulating boss or dummypoint in the form of a semiperforation 126, generally opposite thecentral contact 111. As shown to best advantage in FIG. 30, the endcontacts 1 12 and 1 13 are thinner or lower than the central contact111. The boss or dummy contact 126 corlever 138 having an arm 140 whichextends rearwardly into the casing 102 through an opening 142. The arm140 has a rounded rear end portion 144 which is received in an opening146 formed in the carriage 104.

The lever 138 is pivotally mounted in front of the switch 100 on an arm148 projecting forwardly on a mounting bracket 150, which is riveted orotherwise secured to the casing 102. As shown to best advantage in FIG.21, the switch 100 includes a pivot 152 which extends through an opening154 in the lever 138 and is riveted or otherwise secured to the arm 148.The lever 138 has a forwardly projecting arm 156 which is adapted to beswung vertically to operate the switch. A suitable knob or the like canbe mounted on the arm 156.

As indicated in FIG. 20, the operating arm 156 of the lever 138 isinitially in an intermediate or neutral position andis adapted to beswung upwardly and downwardly to displaced positions. A return springarrangement is provided to bias the lever 138 of the carriage 104 to theneutral position. Various spring means may be employed but theillustrated switch 100 utilizes a torsion spring 160, preferably mountedaround an enlarged'portion 162 of the pivot 152. As shown, the enlargedportion 162 has a head or flange 164 which retains the spring thereon. I

The illustrated torsion spring has arms 166 and 168 which projectrearwardly and are engageable with stops 170 and 172 on the casing 102.The stops 170 and 172 may assume various forms, but are illustrated asears bent forwardly at an inclined angle. The stops 170 and 172 are atthe opposite ends of the opening 142 in the front of the casing 102.Preferably, the spring 160 is initially stressed, so that the arms 166and 168 are pressed rearwardly against the stops.

The arms 166 and 168 of the spring 160 are engageable by connectingelements which are movable with the carriage 104 and the lever 138. Inthis case, such connecting elements take the form of tabs or ears 174and 176, projecting laterally from the lever 138.

The tabs 174 and 176 are arranged so that the lever 138 is locatedinitially in its neutral position. When the operating arm 156 of thelever 138 is swung downwardly, the tab 174 moves the spring arm 166 awayfrom the stop 170. Thus, the spring 160 exerts a force on the tab 174,tending to restore the lever 138 and the carriage 104 to the neutralposition. When the lever arm 156 is swung upwardly, the tab 176 movesthe spring arm 168 away from the stop 172, so that the lever 138 isrestored to its neutral position by the spring 160 when the lever arm146 is released. I I

When the contactor 106 is in its neutral or intermediate position, itengages the contact point 1 11 and the semiperforation 126 as indicatedin FIG. 22. Due to its large size and flat top surface, thesemiperforation 126 has a stabilizing or leveling action upon thecontactor 106, so that it squarely engages the semiperforation and thecentral contact 111. When the contactor 106 is moved downwardly, itengages the contact points 111 and 112, and the semiperforation 126.Upon upward movement of the contactor 106, it engages the contact ppints1 11 and 113, and the semiperforation 126. The present invention may beemployed with various other arrangements involving one or morecontactors and two or more contact points.

FIG. 30 shows the manner in which the contactor 106 tilts or rocks as itis moved away from its neutral position. This tilting action insuresthat the contactor 106 will solidly engage the contacts'l ll, 1 l2, andl 13. As the contactor 106 is moved against the contact 113, the spring130 causes the contactor 106 to tilt about the edge of thesemiperforation 126 as clearly shown in FIG. 30. This tilting action isdue to the fact that the end contacts 112 and 113 are lower than thecentral contact 1 11. The contactor 106 has three points of engagement:with the contacts 111 and 113, and with the edge of the semiper foration126, as shown in FIG. 30. A similar tilting action takes place when thecontactor 106 is moved from its neutral position toward the contact 112.While the illustrated boss or dummy point 126 takes the form of asemipertoration mode of insulating material, it can be in other forms,made of either insulating or conductive material.

Here again, the switch is unusually easy to assemble. The spring 160 andthe lever 138 are assembled on the pivot 152 with the spring arms 166and 168 against the tabs 174 and 176. The pivot 152 is then riveted tothe bracket arm 148. It is an easy matter to insert the carriage 104,the spring 130 and the contactor 106' into the casing 102. The terminalboard 116 is then mounted on the rear of the casing.

The arrangement of the external return spring makes it easy to use astrong and dependable spring, without any size limitation due to thedimensions of the casing 102. The same spring arrangement'can beprovided for various switches, utilizing different arrangements of thecontactor and the points. On the other hand, the spring arrangement canbe hanged without affecting the internal construction of the switch.With the construction of the present invention, the return spring can beprovided at extremely low cost. In each of the illustrated switches, thereturn spring does not engage the mounting bracket, so that the bracketdoes not need to be modified or adapted to accommodate the spring.

In the illustrated switches, the carriage and the operating lever aremovable in both directions from the neutral position. However, theinvention is also applicable to switches in which the lever and carriageare movable in only one direction from the initial position.

Various other modifications, alternative constructions and equivalentsmay be employed, as will be evident by those skilled in the art.

I claim:

1. An electrical switch comprising a casing,

a carriage movable in said casing,

a supporting member connected to the outside of said cas an operatingmember in the form of a lever having pivot means mounting said lever onsaid supporting member, said lever being movable relative to said casingand having an element extending into said casing and engageable withsaid carriage for moving said carriage,

contactor means mounted on and movable with said carriage,

contact means supported by said casing for engagement by said contactormeans, and

a torsion spring disposed outside said casing and mounted along the axisof said pivot means,

said torsion spring having first and second arms extending into saidcasing and engageable with said carriage for biasing said carriageagainst movement in opposite directions.

2. A switch according to claim 1,

in which said casing is formed with an opening through which said armsextend into said casin said casing having stop elements at the ends ofsaid opening and engageable with said arms of said spring formaintaining initial stress in said spring.

3. An electrical switch,

comprising a casing,

a carriage movable in said casing,

contactor means mounted on and movable with said car riage,

contact means supported by said casing for engagement by said contactormeans,

a supporting member connected to the outside of said casan operatinglever extending into said casing for moving said carriage,

pivot means connecting said lever to said supporting member,

a spring mounted on said supporting member, and

two connecting elements on said carriage and movable therewith andengageable with opposite end portions of said spring whereby saidcarriage is biased against movement in opposite directions,

said casing having stop elements engageable with the opposite endportions of said spring.

4. An electrical switch,

comprising a casing,

a carriage movable in said casing,

contactor means mounted on and movable with said carriage,

contact means supported by said casing for engagement by said contactormeans,

a supporting member connected to the outside of said casan operatinglever extending into said casing for moving said carriage,

pivot means connecting said lever to said supporting member,

a torsion spring mounted along the axis of said pivot means and havingtwo end portions in the form of arms, and

two connecting elements on said carriage and movable therewith andengageable with said arms of said spring whereby said carriage is biasedagainst movement in opposite directions.

22%;? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.353 Dated June 6 1972 Inventor-(s) Andrew F Raab It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 5 line 35, "hanged" should read --changed.

Signed and sealed this 26th day of September 1972.

(SEAL) Attest:

EDWARD M.FLETCHER ,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents (5/69) UNITED STATES PATENT QFFICE CERTIFICATE OF CORRECTIONPatent NO. 3,668,353 Dated June 6' 1972 Inventor(a) Andrew F Raab It iscertified that error a ppears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 5 line 35, "hanged" should read --changed--.

Signed and sealed this 26th day of September 1972.

(SEAL) Attest:

EDWARD M.FLETCHER JR. Attesting Officer ROBERT GOTTSCHALK Commissionerof Patents

1. An electrical switch comprising a casing, a carriage movable in saidcasing, a supporting member connected to the outside of said casing, anoperating member in the form of a lever having pivot means mounting saidlever on said supporting member, said lever being movable relative tosaid casing and having an element extending into said casing andengageable with said carriage for moving said carriage, contactor meansmounted on and movable with said carriage, contact means supported bysaid casing for engagement by said contactor means, and a torsion springdisposed outside said casing and mounted along the axis of said pivotmeans, said torsion spring having first and second arms extending intosaid casing and engageable with said carriage for biasing said carriageagainst movement in opposite directions.
 2. A switch according to claim1, in which said casing is formed with an opening through which saidarms extend into said casing, said casing having stop elements at theends of said opening and engageable with said arms of said spring formaintaining initial stress in said spring.
 3. An electrical switch,comprising a casing, a carriage movable in said casing, contactor meansmounted on and movable with said carriage, contact means supported bysaid casing for engagement by said contactor means, a supporting memberconnected to the outside of said casing, an operating lever extendinginto said casing for moving said carriage, pivot means connecting saidlever to said supporting member, a spring mounted on said supportingmember, and two connecting elements on said carriage and movabletherewith and engageable with opposite end portions of said springwhereby said carriage is biased against movement in opposite directions,said casing having stop elements engageable with the opposite endportions of said spring.
 4. An electrical switch, comprising a casing, acarriage movable in said casing, contactor means mounted on and movablewith said carriage, contact means supported by said casing forengagement by said contactor means, a supporting member connected to theoutside of said casing, an operating lever extending into said casingfor moving said carriage, pivot means connecting said lever to saidsupporting member, a torsion spring mounted along the axis of said pivotmeans and having two end portions in the form of arms, and twoconnecting elements on said carriage and movable therewith andengageable with said arms of said spring whereby said carriage is biasedagainst movement in opposite directions.